[The role of low-molecular-weight nitrogen compounds in the osmotolerance of Rhodococcus erythropolis and Arthrobacter globiformis].

Investigations showed that Rhodococcus erythropolis E-15 and Arthrobacter globiformis 2F cells respond to osmotic shock by increasing the synthesis of free amino acids, primarily glutamic acid (80% of the intracellular free amino acid pool). The osmoprotective role of glutamic acid follows from its beneficial effect on the growth of bacteria in high-salinity media. It was found that the addition of this amino acid to the growth medium at a concentration of 2 mM shortened the lag phase and increased the growth rate and biomass yield of either of the two bacteria.

[Bacterial succession on n-alkanes under the conditions of sulfate reduction].

The dynamics of species composition of a hydrocarbon-oxidizing bacteriocenosis of a ground suspension of Mozhaisk Reservoir has been studied. The bacteriocenosis was undergoing development in a paraffin film (model association composed of sulfate-reducing bacteria and hydrocarbon-oxidizing bacteria). The type of bacterial succession did not depend on the depth, from which ground samples were collected.

[Extracellular metabolites of hydrocarbon-oxidizing bacteria as a substrate for sulfate reduction].

The relationship between bacterial oxidation of hydrocarbons and sulfate reduction was studied in the experimental system with liquid paraffin was used as a source of organic compounds inoculated with silt taken from a reservoir. Pseudomonads dominated in the hydrocarbon-oxidizing silt bacteriocenosis. However, Rhodococcus and Arthrobacteria amounted to not more than 3%.

[Inclusion of labeled precursors of macromolecular compounds in the mycobacterial cells in the presence of DP-2 preparation].

The changes in the inclusion of 3H-phenylalanine, methyl-3H-thymidine, [2-14C]-thymidine and [5-3H]-uridine in the cells of pathogenic M. bovis-8, opportunistic M. fortuitum and saprophitic M.

Investigation of the lipids of saprophytic mycobacteria in the U.S.S.R.

Three trends in the investigations of the specific lipids of rhodococci and related microorganisms are reflected: isolation and structural determination of new complex lipids, elucidation of the role of specific lipids in the cells and application of lipid composition for diagnostic studies of rhodococci and related organisms. Two groups of peptidolipids, differing in chromatographic mobility and peptide chain structure, have been found in the cells of Rhodococcus erythropolis. The compounds within each group differ in acyl moieties.

[Hydrocarbon-oxidizing microflora from the water of the Baltic sea and Kurshsky bay polluted after a fuel oil spill].

Microbiological studies were conducted in the water of the Baltic sea and the Kurshsky bay polluted with mazut as the result of a tanker wreck in November 1981 as well as in the water of nonpolluted regions. Within the summer of 1982 and 1983, 755 bacterial strains were isolated from water samples taken at three different depths. Bacteria belonging to the genera Pseudomonas, Rhodococcus + Mycobacterium and Arthrobacter predominated in the hydrocarbon-oxidizing cenoses of the Baltic sea and the Kurshsky bay.

[Biological activity of a polar lipid of Clostridium butyricum spores].

A fraction of polar lipids was isolated from spores of the anaerobic bacterium Clostridium butyricum 35/11 exerting a noticeable radioprotective effect. The main biological activity of spore extracts was associated with this fraction. The fraction of polar lipids inhibited autolysis of the bacterial cell walls.

[Esterase activity of hydrocarbon-oxidizing bacteria].

The activity of esterase was studied in bacteria oxidizing hydrocarbons and belonging to the genera Rhodococcus, Arthrobacter and Pseudomonas. Indophenyl acetate was used as a substrate of the reaction catalysed by the enzyme. Exocellular esterases were not found.

[Free mycolic acids of the cells of coryneform and Nocardia-like bacteria].

The composition of free mycolic acids was studied in the cells of Brevibacterium ammoniagenes ATCC 6871, B. flavum 22, B. stationis ATCC 14403, Corynebacterium divaricatum ATCC 14020 and Rhodococcus maris IMV 195.

[Bacterial interaction in a culture containing Pseudomonas and Mycobacterium in relation to hydrocarbon oxidation].

An experimental association of Pseudomonas and Mycobacterium was employed for a more complete oxidation of a hydrocarbon substrate. The maximum effect of combined cultivation (74% vs. 50 and 47% in the pure cultures of Mycobacterium and Pseudomonas, respectively) was obtained under steady-state conditions.

[Chemical composition and role of Pseudomonas aeruginosa peptidoglycolipid in hydrocarbon assimilation].

Pseudomonas aeruginosa P-20 releases a lipophilic compound during growth in a medium with hexadecane. The compound was shown to be a peptidoglycolipid. The peptide moiety consists of 7 amino acids: lysine, aspartic and glutamic acids, serine, proline, valine and leucine.

[Role of emulsification in the process of hydrocarbon absorption by Pseudomonas aeruginosa cells].

Lipophilic biopolymers from the cell walls of saprophytic mycobacteria were shown to stimulate the process of hydrocarbon assimilation by Pseudomonas aeruginosa cells. This should be attributed to the fact that bacterial peptidoglycolipids emulsify a hydrocarbon facilitating the contact between it and the cells. It has been found experimentally that P.

[Effect of petroleum hydrocarbons on the viability of cyanobacteria in association with oil-oxidizing bacteria].

An important aspect in the problem of interactions between microorganisms in the conditions of oil pollution is how to preserve the viability of phototrophic organisms if active oil-oxidizing microflora is present in the environment. As was illustrated using a closed model ecosystem, the association 'cyanobacteria--oil-oxidizing bacteria' is capable of withstanding the negative effect of oil pollution, but within the range of hydrocarbon concentrations which can be oxidized by oil-oxidizing bacteria during a very short time. The biological equilibrium in the ecosystem was maintained and the number of viable cells of the phototrophic component in the ecosystem increased if the oil-oxidizing bacteria started to function at the same time as toxic compounds commenced to produce their effect on the microorganisms.

[Chemotactic reactions of a paraffin-oxidizing strain of Pseudomonas aeruginosa].

The reactions of chemotaxis were studied in a paraffin-oxidizing Pseudomonas aeruginosa strain using the method of migration in viscous media. Diesel fuel and paraffin become attractants only if they are contaminated with hydrocarbon-oxidizing mycobacteria. A suspension of mycobacterial cells as well as their lipids (peptidoglycolipids, wax, triglycerides, methyl esters of mycolic acids) are attractants, too.

[Lipids of a paraffin-oxidizing strain of Pseudomonas aeruginosa].

The qualitative and quantitative composition of lipids was studied in a paraffin-oxidizing Pseudomonas aeruginosa P-20 strain. The content of free lipids was 7% of the dry biomass weight in a medium with hexadecane and 6.7% in a medium with glucose.

[Effect of cyanobacteria excretions and cell biomass on hydrocarbon-oxidizing mycobacteria].

The presence of cyanobacterial cells and their exocellular excretions in an aqueous ecosystem stimulated biodegradation of diesel fuel. As was established using the technique of complete factor analysis, nitrogen addition to the medium and the presence of cyanobacterial cells in it are important for the growth of oil-oxidizing bacteria, while exocellular excretions of the cells are not sufficient for such a growth. The mycobacterial growth depended, to a certain extent, on the age of cyanobacterial cultures.

[Arctic pigmented mycobacteria and their role in the oxidation of petroleum hydrocarbons].

Red-orange Mycobacterium species (the rhodochrous group) were isolated from the water of the Arctic regions; they were described, and the structure of lipids and the assimilation of oil products of low temperatures were comparatively studied in the arctic water and soil Mycobacterium species. The composition of usual fatty and mycolic acids was studied in two strains growing in a medium with hexadecane. Palmitic acid prevailed among fatty acids in the both strains; mycolic acids were represented by the compounds C34:0 and C34:1 (Mycobacterium brevicale) and C32:0 and C:34:0 (Mycobacterium sp.

[Substrate-induced changes in Mycobacterium paraffinicum cells and cell membranes].

The method of spectroscopy of attenuated total reflection (ATR) range was used to study the dynamics of biochemical changes of both the whole cell of Mycobacterium paraffinicum 134 and its outer layer depending on the type of growth substrate. The cells and their outer layers were shown to vary significantly in their composition upon growth in different media. When the cells were cultivated in a medium with glucose, the biosynthesis of structural lipids of the cell wall, viz.

[Triglycerides of saprophytic mycobacteria].

Triglycerides produced by mycobacteria and arthrobacteria grown in media with hexadecane or glucose were studied by mass spectrometry. In all of the cases, triglycerides were mixtures of homologues. The triglycerides of Arthrobacter ceroformans grown in a medium with hexadecane contained 90% of tripalmitate and 10% of a mixed triglyceride comprising two residues of palmitic acid and one residue of palmitoleinic acid.

[Microbiologic oxidation of diesel fuel by the total factor experiment method].

The effect of nitrogen, phosphorus, glucose and temperature on the assimilation of diesel fuel and the biomass yield of Mycobacterium mucosum was studied by the method of complete factor experiment. The concentration of nitrogen and phosphorus were shown to be most important for the above processes. The growth dynamics of the culture was studied as well as the utilization by it of diesel fuel and glucose added to the medium separately or in combination.

[Lipids of saprophytic bacteria produced during growth on a complex organic substrate].

The composition of lipids and the structure of mycolic acids were studied in Mycobacterium lacticolum var. aliphaticum isolated from soil and grown on MPB. The lipids of all strains were found to contain phosphatidyl inositol mannosides, phosphatidyl ethanolamine, cardiolipin, mycolic and common fatty acids, triglycerides, wax, and several unidentified compounds.